"Successful" dualboot... but now kernel panic
 

I've successfully gotten my PC to give me the choice between booting Win XP Pro or Knoppix 4.0 with with the Window's NTLOADER, and Win XP boots successfully. But when I try to boot Knoppix I get a "kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(3,2)".

I've searched around and found some people with the same problem and have resolved the issue. But it may as well have been in a foreign language... I either didn't understand what they were saying or it didn't fix the problem.

Can someone please give me some stuff to try and dumb it down enough so that I can follow it. Be as detailed as possible (assume I know nothing... I practically do).

Thank you for the help...

"Unable to mount root fs on unknown-block(3,2)" This is not a kernel panic, it is an error from the boot loader. The boot loader needs to know where to boot from.

Is your Knoppix on the fourth hard drive, third partition? The block should be where /boot resides, the numbers are referenced from zero, so (0,0) would be first hard drive, first partition. Well, that is how grub see it.

No, the first partition on the first hard drive is linux swap and the second is knoppix itself, followed by Win XP on the third partition. NTLOADER boots grub from the knoppix root partition (i.e. NTLOADER loads C:\bootsect.lnx which loads GRUB and provides the "knoppix" boot menu).

I don't remember exactly what the grub configuration looks like, the first line is something along the lines of "boot hd0,1" and the second line is "kernel root=/dev/hda2" plus all the "other stuff". I don't know if that's exactly right, but the point is that it's pointing to the right hard drive and partition... so why I'm getting "unknown-block(3,2)", I don't know.

I have never messed with NT loader, but block appears to mean a block device, like a hard drive. If it is like grub, (3,2) = 4th HD, 3rd partition. I would look at the setting of the NT loader and find something that looks like "block (3,2) and change it to, (0,1) which is 1st HD, 2nd partition, which is where you said Knoppix was at. I would set the linux boot to have the correct infomation you need.

First line of grub should be -> root (hd0,1)

For future reference, a swap partition is placed at the end of the drive or the last partition, due to the slow latency of the outside of the disk. The swap doesn't need to be responsive, but loading data and files for programs is more important and is placed first in partition order.

If I go here: /mnt/hda2/boot/grub, and open up menu.lst... I get a list of my menu options (obviously)... which are:

Plus this one for Windows:



NT Loader just chainloads (sorry if I'm not using the proper terminology) grub, which is located in the knoppix root partition instead of in the MBR. Once I choose knoppix from the first boot screen, it loads grub and gives me all of the choices listed above. Only after I select one of those do I get the "kernel panic" message. And each of those point to hd0,1. Is there somewhere else I should be looking?

The hard drive and partitions look correct.

Where is the rest of the name of the kernel and initial ram disk? You can find the names of them by editing the line. If you erase everything back until it says kernel /boot and then press <tab> grub will then display the possible choices. The same for the initrd line.

The two vmlinuz files are vmlinuz and vmlinuz-2.6.12, and the same for initrd... initrd.img and initrd.img-2.6.12.

I get the same error regardless of which ones I use. And the same thing regardless of whether or not I delete all of the extra "boot options" after /boot/vmlinuz

When I take off the very end of the kernel line (the "quiet" and "vga=791" parts) it shows these two lines just before the error:

RAMDISK: compressed image found at block 0
RAMDISK: incomplete write (-28 != 32768) 4194304

I still think you maybe point to the wrong partition. If not, then you will need to check the file system.
Can you give me the results from /sbin/fdisk -l ?

And df command?

For the fdisk I got:

and for the df I got:

Thanks. I didn't see anything wrong. Have you fsck command on your hard drive? boot with knoppix live and don't mount the drive and then check it.

Never mind about the log file, your logger isn't running.

All I got when I ran fsck was "fsck 1.38 (30-Jun-2005)" and I'm assuming that there's supposed to be more to it than that.

And was this:

...in reference to something I said?

The logger statement: I orginally posted about checking your log file, but later I thought that the logger thread in the kernel was probably not running yet, because it never loads the kernel. The log file is located at /var/logs/messages

The /sbin/fsck should syntax like this
Try the device drive -> /sbin/fsck /dev/hdc

Can you tell me the label of your partitions?
Expect any swap partition to return an error.

Ok, I got errors on the first and third partitions because the first is my swap and the third is my NTFS partition for Windows... here's what I got for the second one:


e2label wouldn't work because none of them are ext2 partitions (at least, that's why I'm assuming it didn't work). I fired up qtparted and it says the the linux-swap and NTFS partition labels are blank and for the reiserfs partion (on which Knoppix resides) the label is "No label" rather than just a blank.

And as a side note: I don't know whether this is important or not, but qtparted shows the status of the NTFS partition is "Active" and the unpartitioned space is "Hidden", but the status of the reiserfs and the linux-swap partitions are blank... right-clicking brings up a "Set active..." option.

if everything else fails, you kernel is configure with the root filesystem as a module. Support for the root filesystem needs to be compiled into the kernel, as part of the kernel, not a module. Did you select a root filesystem that is not the default? This is what happens when you do that. Reinstall linux with the default filesystem for root. Typically, in linux, all filesystem support is modular, except the root filesystem. That is compiled into the kernel. Some distros don't catch that you changed from the default, and recompile the kernel. Debian is one that does this correctly.